But what faith can we learn from these false teachers when, in consequence of separating from the Church, they have no rule of faith? ... How often Calvin changed his opinions! And, during his life, Luther was constantly contradicting himself: on the single article of the Eucharist, he fell into thirty-three contradictions! A single contradiction is enough to show that they did not have the Spirit of God. "He cannot deny Himself" (II Timothy 2:13).

In a word, take away the authority of the Church, and neither Divine Revelation nor natural reason itself is of any use, for each of them may be interpreted by every individual according to his own caprice ... Do they not see that from this accursed liberty of conscience has arisen the immense variety of heretical and atheistic sects? ... I repeat: if you take away obedience to the Church, there is no error which will not be embraced.

St. Alphonsus